Important sources of genomic alterations are mutations, or spontaneous errors of DNA replication, [ 37, 38] that occur despite the existence of a wide range of mechanisms ensuring DNA repair and correct replication [ 39].
It is likely that this must occur on a background of increased Wnt signalling, such as that provided by germline Apc mutations, or by spontaneous somatic mutation of genes such as β-catenin in older animals.
To further resolve whether high levels of variation in centromeres result from the action of gene conversion or spontaneous mutation, I investigated the mutation spectrum in centromere sequences.
There are no detrimental effects on growth, progeny number or spontaneous mutation rate.
The difference in cleavage sites may in turn be a result of natural selection or spontaneous mutation.
In 2008, while both A/Brisbane/59/2007-like and A/Hong Kong/2652/2006-like viruses (H1N1) were cocirculating, we detected amantadine and oseltamivir resistance among A/Hong Kong/2652/2006-like viruses (H1N1), caused by genetic reassortment or spontaneous mutation.
We cannot exclude the possibility that some of the phenotypes from M. musculus may not result from protein disruption/inhibition, for example, it is possible that chemical or spontaneous mutation could result in constitutive activation of a protein or a gain-of-function.
Autosomal-dominant inheritance or spontaneous mutation in a single copy of COL3A1 resulting in haploinsufficiency has been linked (although not exclusively) with vascular complications in EDS IV patients, and thus, the +/ Col3a1▵ mutant may more closely recapitulate the human condition than the previously generated knockout.
This was possible due to a considerably low mutational load resulting from spontaneous mutation or low intensity UV mutagenesis followed by a very restrictive selection.
Recent observations in mice with either engineered or spontaneous mutations in the dystonin gene indicate that BPAG1-b serves as a cytolinker important for the establishment and maintenance of the cytoarchitecture and integrity of striated muscle.
